PERMFILE51112

• Permit No: C1982057
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: SEDIMENTATION STRUCTURE 006 AND PRE SETTLING BASIN PHASE IV DESIGN
• Section_Exhibit Name: TAB 13 ATTACHMENT 13-4C
• Media Type: D
• Archive: No

Spillways
Sediment Pond 005 has two separate spillways; a principal avid an eme rgency. Please see
ExhiGit 13-5B for location and design of spillways. The principal spillway consists of a
2a" diameter drop inlet co ri ugatrd metal p1 E.e !CI-0FI with trash screen. t4aximum elevation
(peak stage) with the Fa sage of the 10-year, V-ho ui even[ wi 11 be %0"15.9, [his Leaves
0.1 feet tc [he eme rg en,:y spillwcy crest.
The ems rq ency spillway for pond OU6 consists of n prapped [ra pe roidal charms). Assuming
the principal spillway pipe was pl~lgged, and the Fre-SeLiling Basin was bypassed, the
trap=_-~•idal channel could safely pass the runoff '/ol urn= fi~~m [he LS-y =a r, '.'.4-hour st arm.
Feat stage e1e'/ati~n with the passage of the ~5ryea~ sic•rm is "101. 9, this leaves 2.1
feet of freeboard to [he [op of emGenkment.
The Fre-Settling Basin has one spillway which consists cf a riprapped irape.c idal
channel. The [raF~F ZO idal channel cou bi safe l}' I•ass the runoff volume from the 25-year,
?4-hour storm. Peak stage elevat u•n 'with the passage of the -5-year storm is n118. 6,
this leave; l.a fee[ of iieeboa rd t~• the crest of the Ga sin. Please refer to Addendum 1
for caua•:ities of both spillways during passage of the 10 and S-year storm events.
Table 13-a r-_a and Addendum [ prssen[s the desi•3n ~--a lculan nns for the prima pal and Goth
emergency spillway.
TI-.B LE 13-4C-a
F'FIIICI FA.L FtID EMEFGEIIC'i SE'I LLWAi DAT F. SlJ lil-1AF'i
Pend 005 - F'HASE IV
Principal S1•i ilwa y:
Type
In1e[ Elevation
Length
Diameter
Slope
lU-yea[, 24-bout Peak Stage
Emergency Spillway:
Typ=_
B~LLGm WidCh
Length
Side Slopes
Dr~•p inlet ICI-0FI
7fJ71.5
150 feet
[9 inches
d . i18
~o~s.a
Traps z~~idal Channel
15 feel
50 feet
3H:lV
8 Feciscd n3/02/98
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